The present invention relates to an apparatus for providing material processing, such as finishing, of an article through high speed centrifugal and rotational motion.
In recent years, a realization has developed regarding the importance of surface finishing in the manufacture of a product. For many products it is desirable, and in some cases mandatory, that the products be finished so as to have a smooth surface without any reduction in the material characteristics of the product that are essential for its intended purpose. Various processes have been developed over the years to provide surface finishing.
Some finishing machinery use the centrifugal force imparted by a rotating vessel to finish products. A number of these machines subject objects to both centrifugal and rotational forces using a complicated set of gears. These types of machines are limited to a particular ratio of revolutional speed to rotational speed. Also, the construction of these machines is complicated requiring many moving parts, and are generally extremely noisy. Other types of machines create centrifugal forces by revolving a vessel around a shaft and creating rotational forces using a belt wrapped around the shaft and the exterior of the vessel. The speed of the belt is related to the speed of the shaft. Overheating is common in these types of machines.
One successful machine using both centrifugal and rotational forces in a simple design without a system of gears and which can be operated at very high speeds is disclosed in U.S. Pat. No. 5,355,638 to Hoffman, the disclosure of which is hereby incorporated by reference in its entirety. As disclosed in that ""638 patent, the centrifugal finisher (or polisher) has an outer vessel that is rotatable, and at least one inner vessel that is revolved about the axis of the rotatable outer vessel and rotated about its own axis. A traction surface exists between the inner surface of the outer vessel and the outer surface of the inner vessel. The traction surface allows the outer vessel to restrain the inner vessel while the inner vessel experiences centrifugal forces. This machine simultaneously causes the rotational movement of the inner vessel to transfer momentum from the outer vessel to the inner vessel because the outer vessel is rotated at a different speed and potentially a different direction than the rotational movement of the inner vessel, thus causing the revolution of the inner vessel.
The ""638 patent also discloses an apparatus where a center drive can be used for rotating the outer vessel and the inner vessel. One drawback of this type of machine is its size limitation because the outer vessel must be designed to rotate. For large objects, this becomes impractical and expensive. Additionally, because of the interaction between the inner and outer vessels, it is not possible to control rotation of the inner vessel without controlling rotation of the outer vessel. Also, the operation of the whole unit is constrained by the total RPM that the unit can operate under, and particularly the speed of the outer vessel, which can be difficult to manage when greater diameters are required.
Another successful machine using both centrifugal and rotational forces and which addresses the limitations of the device in the ""638 patent is disclosed in U.S. Pat. No. 5,848,929 to Hoffman, the disclosure of which is hereby incorporated by reference in its entirety. The ""929 patent discloses a centrifugal finisher with a fixed outer vessel which permits much larger objects to be finished without the need to apply excessive energy and force to the unit. Additionally, the device in the ""929 patent permits the inner vessel to be removed so that vessels of various diameters can be used in the unit without necessarily having to change the outer vessel.
Due to restrictions on speed, conventional centrifugal machines are limited in the types of material processing they can perform on objects, Primarily, these types of machines are limited to surface finishing of objects and, using the machines described in the ""638 and ""929 patents, surface hardening. The speed restrictions prohibit these machines from being used to provide mixing of unlike materials. In order to mix such materials, conventional methods include explosive combining wherein sufficient force is created by a preset explosion to cause the unlike materials to combine.
While both the ""929 patent and the ""638 patent describe apparatus that provide high speed centrifugal and rotational finishing, the ultimate speed of the finishing devices is limited. A need, therefore, exists for an improved high speed centrifugal finisher. Also, it would be beneficial if a centrifugal-type machine could, by means of its high speed of operation, produce intermixing of unlike materials.
The present invention relates to an apparatus for performing high speed processing of a workpiece through the use of centrifugal and rotational motion. The apparatus includes an outer vessel having an inner surface and a central axis.
At least one intermediate vessel is located within the outer vessel and has an outer surface which contacts the inner surface of the outer vessel.
At least one inner vessel is positioned within the intermediate vessel and adapted to receive an object to be subjected to a manufacturing process. The inner vessel is located at a position within the intermediate vessel such that the central axis of the inner vessel is spaced apart from the central axis of the outer vessel.
A drive system is engaged with the intermediate vessel to control the rolling of the intermediate vessel along the inner surface of the outer vessel. The rolling of the intermediate vessel causes the inner vessel to rotate about its axis and the axis of the outer vessel.
The present invention is designed to produce significant centrifugal and rotary loads on the object contained within the inner vessel, providing a novel system for processing materials.
The foregoing and other features and advantages of the present invention will become more apparent in light of the following detailed description of the preferred embodiments thereof, as illustrated in the accompanying figures. As will be realized, the invention is capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive.